Fuse-cap.



G. F. SPERY.

FUSE CAP.

APPLICATION FILED APR. 10, 1911.

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COLUMBIA PLANOGRAPH CO" WASHINGTON. D. C.

CHARLES F. SPERY, OF CHICAGO, ILLINOIS.

FUSE-CAP.

Specification of Letters Patent. Patented All. 22, 1911.

Application filed April 10, 1911. Serial No. 620,124.

To all whom it may concern:

Be it known that I, CHARLES F. SPERY, a citizen of the United States, residing in Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Fuse-Caps, of which the following is a specification.

The invent-ion relates in general to a fuse cap adapted to be attached to a suitable fuse and containing a supplementary explosive charge which is ignited by the fuse, for exploding a maincharge.

More particularly the invention relates to the means for securing the fuse to the cap so as to obtain a tight water-proof joint, and also a joint that may be easily and quickly connected, irrespective of the frayed or broken condition of the end of the fuse, or with fuses of slightly varying diameters.

To these ends the invention consists of a fuse cap as shown in the drawing, in

which Figure 1 is a side elevational view of my improved cap and a fuse; Fig. 2 is a similar View as Fig. 1 showing a slightly modified form; Fig. 3 is a side elevational view of another modified form; Fig. 4 is a side elevational view of a fuse; Fig. 5 is a sectional View of my improved fuse cap with fuse attached; Fig. 6 is a side elevational view of another modified form; Fig. 7 is a side elevational view of a twopart fuse cap with fuse attached.

Referring now more particularly to the drawing, my preferred form of construction consists of a hollow shell 10 having one end closed and the side walls of its open end flared as shown at 11, so that the diameter of the shell at its open end is slightly greater than its cylindrical diameter. The shell has threads 12 formed therein and the flared end preferably has a knurled surface 13.

The fuse 14 constitutes no part of the invention and generally consists of some form of water-proof material inolosing an inflammable substance indicated at 15, or the fuse may consist of electrical wires 16 within an insulating medium 17. The fuse must be connected to the cap so as to prevent water entering the cap and destroying the explosive charge 18 therein; and it is to the proper securing of the parts together that my invention is directed. As the waterproof material, or the insulating medium, is liable to a certain extent, I form threads 12 in the shell and by inserting the fuse into the shell and turning one member rela tive to the other, the threads on the shell engage the pliable fuse cover and the latter may be thereby screwed into the shell until its end comes in contact with, or is near the explosive charge, thereby forming a tight moisture and water-proof joint, as well as a firm engagement between the two parts, preventing the withdrawal of the fuse from the shell except by unscrewing the same. It is, of course,'understood that the shell, with the exception of its flared end, is of sub-- stantially the same diameter as the diameter of the fuse and the pliability of the mate-v rial from which the fuses are made, permits displacement so as to allow the end of the fuse to conform with the interior threaded surface of the shell as indicated at 19 in Fig. 4.

In Fig. 1 the diameters of the threads are substantially equal, but in Fig. 2 I have shown the threads formed partly upon the flared surface of the shell, and partly upon the cylindrical portion, which enables the threads to more readily and gradually grip the end of a fuse.

In Fig. 3 the flared end of the shell has been omitted, thereby showing the invention in its simplest form, but is not deemed so practical as the structures shown in Figs. 1 and 2, because the ends of fuses frequently become frayed or broken in such a manner that they will not readily enter the open end of a shell when the diameters of the shell and fuse are substantially the same.

In Fig. 6 I have illustrated a shell in which the threads are formed upon the flared end and extend down to the cylindrical portion of the shell, to which construction fuses of varying diameters may be readily secured, as a firm engagement between parts will take place where two threads at least can be embedded in the pliable coating of the fuse, and consequently, a fuse of a greater diameter than the cylindrical portion of the construction shown in Fig. 6 might be secured thereto.

In Fig. 7 a still further modified form is shown consisting of a shell 20 adapted to contain the explosive charge, slightly flared at its open end, and a shell 21 open at both ends and having threads 22 formed thereon for engaging the fuse 14; the shell 21 have ing slightly converging side Walls and adapted to enter the shell 20 and have a Wedging engagement therewith.

In practical use the fuse caps or shells containing an ignition charge are sold to users, and when an explosive charge is to be ignited, such as in blasting work, a fuse of either the burning type or the electrical tvpe is secured to the shell which is then placed against the explosive material or main explosive charge. The fuse is then lighted, or the electric circuit closed, exploding the charge in the cap, which in turn explodes the main charge.

It is of course obvious that there are many other forms of construction in which my invention might be embodied and Therefore without limiting myself to the particular forms herein shown and described, I claim:

1. A fuse cap comprising a shell for receiving an ignition charge having a cylindrical body and an outwardly flared mouth portion and threads formed partially on said body and partially on said mouth portion.

2. A fuse cap comprising a shell for receiving an ignition charge having a cylindrical body and a flared mouth portion provided with a knurled exterior surface and threads formed on said body near said flared portion for engaging a fuse.

3. A fuse cap comprising a shell for receiving an ignition charge having a closed end and an open end, the walls of the shell being slightly flared outward toward its open end, and a cylindrical fuse-attaching shell having converging walls toward one end for complementary engagement with the shell carrying the ignition charge, said fuseattaching shell having threads formed thereon for engaging a fuse.

CHARLES F. SPERY.

Witnesses:

JAMES R. OFFIELD, SADIE M. RYAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

